1. Field of the Invention
The present invention relates to an apparatus for inputting the image and the method of inputting the same utilized in the field of the image processing in general.
2. Prior Art
Recently, in the field of the image processing, technologies relating to an imaging device make a rapid progress. As the background of such a rapid progress, there is a disadvantage that the apparatus for inputting the image with the imaging device does not necessarily satisfy the demand of the imaging at a high speed, a sufficient high sensitivity and a high resolution. In general, the limit of the input speed, the sensitivity and the resolution of the apparatus corresponds to the limit which an image provided by the current broadcasting or communication standard can be easily achieved technologically or economically.
Until now, inputting the image is input to the imaging device at a high sensitivity and a high resolution by the increase in the number of pixels and/or by the magnification of a photodetecting section. In this case, however, there are disadvantages (a) to (c) as described below.    (a) The increase in the number of pixels and/or the magnification of the photodetecting section bring the increase in the area of the imaging device, and thus reduce the operating speed of the apparatus.    (b) The increase in the number of pixels and/or the magnification of a photodetecting section make an integrated circuit large-scale, and it is known that faults and/or defects in the integrated circuit exponentially increase with the large-scale of the integrated circuit. As a result, there are technological and economical difficulties in making the remarkable large-scale circuit in order to form a single imaging device.    (c) The complexity in the design of the integrated circuit also exponentially increases with the large-scale integrated circuit.
Therefore, at the present technologies, it is very difficult to input the image to be an object into an imaging device at a sufficient high resolution and a sufficient high quality by means of a single imaging device, and thus it is necessary to establish the image input technology without a technological or economical limit.
On the other hand, in order to fulfill the requirement of the image input at a high speed, a high sensitivity and a high resolution, a method of dividing an optical system using a mosaic CCD array or a quadrangular-pyramid mirror has been proposed so that the requirement can be achieved by combining the optical system and a plurality of imaging device with one another, though it is almost impossible to achieve the requirement with a single imaging device (e.g. refer to non-patent document 1).
The method using the mosaic CCD array is used mainly in the field of the astronomy according to proposal of the University of Tokyo. In this case, the CCDs are arranged at the intervals to which these CCDs can be attached, and when the area can be imaged at one time, all of the area is imaged by moving the CCDs. In the method using the mosaic CCD array, however, because of the mechanical movement of the CCDs, it is difficult to perform a precise joint of the joint face of CCDs to each other and the input of the dynamic image (the moving picture).
The method using a quadrangular-pyramid mirror is utilized in the Hubble Space Telescope in the field of the astronomy and is utilized by Nippon Telegraph and Telephone Corporation in the field of the printing (e.g. refer to non-patent document 2). However, because it is diffcult to make an angle between sides of the quadrangular-pyramid mirror with a high accuracy, it is also difficult to divide one light beam into a plurality of the light beams, particularly, when the first-order image formation does not exist, an object on a focal point can be formed as an image, but an object at another position than the focal point is formed as multiple divided images or as a partially lost image. In other words, the method using a quadrangular-pyramid mirror has a characteristic of dividing the image into four parts of the image and is suitable for inputting a two-dimensional static image to be divided into four parts of the image.
The abstract of the above-mentioned methods are as follows:    (i) The method using a mosaic CCD is not suitable for inputting the dynamic image because of accompanying the mechanical movement of the CCDs.    (ii) The method using a quadrangular-pyramid mirror has a characteristic of dividing the image into four parts of the image and is suitable for inputting a two-dimensional static image to be divided in four parts of the image when the first-order image formation does not exist.
In both cases (i) and (ii), it is difficult to divide the optical image into a plurality of the optical images with a high accuracy. Also, in principle, the imaging device is constituted so as to pick up a single light beam from the optical system by means of the single imaging device, and thus even if these conventional optical system and a plurality of imaging device are combined with one another, it is impossible to make a good combination of the optical system with the plurality of imaging devices.
Also, a method of dividing an optical image with a high accuracy by means of an optical fiber array (see patent documents 1 and 2, for example) and a method of dividing an optical image by means of a beam splitter (see non-patent document 3, for example) have been also proposed.
Further, in the field of graph theory, there is the assumption relating to the possibility of distinguishable coloring a graph in four colors, namely, the problem that “any map drawn on a plane or spherical surface can be distinguished with four colors so that adjacent countries to each other are different from each other in color, such a problem being famous as a problem of separating countries by color in a world map (non-patent document 4 for example), and there is also a fact that any countries can be actually distinguished with four colors (see non-patent document 5 for example).
Patent document 1: U.S. Pat. No. 4,323,925 Specification (FIG. 1)
Patent document 2: U.S. Pat. No. 5,134,680 (FIG. 5, FIG. 6)
Non-patent document 1: Jill Knapp and five others, “The Sloan Digital Sky Survey Project Book” disclosed online on Aug. 11, 1999 in the Astrophysical Research Construction, retrieved on Nov. 29, 2002 on the Internet at www.astro.princeton.edu/PBOOK/welcome.htm (FIG. 8.2, FIG. 8.4)
Non-patent document 2: “Wide Field and Planetary Camera 2 Instrument Handbook for Cycle 12”, Version 7.0, SPACE TELESCOPE SCIENCE INSTITUTE, October, 2002 (FIG. 2.1, FIG. 2.2)
Non-patent document 3: Hiroyuki Ogino et al., “Development of a High-Resolution Multiple Image Microscope Apparatus”, the Institute of Television Engineers of Japan, Technical Report Vol. 20, No.59, pp.7-12, Nov. 15, 1996 (FIG. 2)
Non-patent document 4: Frank Haraey, “GRAPH THEORY”, ADDISON-WESLEY, pp.131-135, (THE FOUR COLOR CONJECTURE), 1969
Non-patent document 5: Kenneth Apple et al., “The Solution of the Four-Color-Map Problem”, Scientific American, vol.237, No.4, pp.108-121, October, 1977
As already stated, it is difficult to realize an imaging apparatus satisfying the condition of inputting the image at a high sensitivity, a high resolution and a high speed by means of a single imaging device, and this can be explained on the basis of the theory of algorithm in theory. In order to realize an imaging apparatus satisfying such a condition without technological and economical difficulties relating to making a large-scale integrated circuit, it is necessary to put a technology of well combination of the optical system with a plurality of imaging devices to practical use. Such a requirement is particularly remarkable in the field of a remote medical treatment (e.g. the telemicroscopy, especially the telepathology) necessary to process an image with a high accuracy in real time, and at the present stage, it is very difficult to constitute an image input apparatus at a high speed, a high sensitivity and a high resolution enough to be applied to the field of the remote medical treatment.